3 files changed, 33 insertions, 2 deletions
diff --git a/supervisor/filesystem.h b/supervisor/filesystem.h
index 76f235f47..c7c951a5e 100644
--- a/supervisor/filesystem.h
+++ b/supervisor/filesystem.h
@@ -31,6 +31,10 @@
 
 #include "extmod/vfs_fat.h"
 
+extern volatile bool filesystem_flush_requested;
+
+void filesystem_background(void);
+void filesystem_tick(void);
 void filesystem_init(bool create_allowed, bool force_create);
 void filesystem_flush(void);
 bool filesystem_present(void);
diff --git a/supervisor/shared/autoreload.c b/supervisor/shared/autoreload.c
index 2a7fd1e9d..14b21902c 100644
--- a/supervisor/shared/autoreload.c
+++ b/supervisor/shared/autoreload.c
@@ -29,9 +29,10 @@
 #include "py/mphal.h"
 #include "py/reload.h"
 
-volatile uint32_t autoreload_delay_ms = 0;
-bool autoreload_enabled = false;
+static volatile uint32_t autoreload_delay_ms = 0;
+static bool autoreload_enabled = false;
 static bool autoreload_suspended = false;
+
 volatile bool reload_requested = false;
 
 inline void autoreload_tick() {
diff --git a/supervisor/shared/filesystem.c b/supervisor/shared/filesystem.c
index 0ef978ef2..68c6f4749 100644
--- a/supervisor/shared/filesystem.c
+++ b/supervisor/shared/filesystem.c
@@ -37,6 +37,30 @@
 static mp_vfs_mount_t _mp_vfs;
 static fs_user_mount_t _internal_vfs;
 
+static volatile uint32_t filesystem_flush_interval_ms = CIRCUITPY_FILESYSTEM_FLUSH_INTERVAL_MS;
+volatile bool filesystem_flush_requested = false;
+
+void filesystem_background(void) {
+    if (filesystem_flush_requested) {
+        filesystem_flush();
+        filesystem_flush_requested = false;
+    }
+}
+
+inline void filesystem_tick(void) {
+    if (filesystem_flush_interval_ms == 0) {
+        // 0 means not turned on.
+        return;
+    }
+    if (filesystem_flush_interval_ms == 1) {
+        filesystem_flush_requested = true;
+        filesystem_flush_interval_ms = CIRCUITPY_FILESYSTEM_FLUSH_INTERVAL_MS;
+    } else {
+        filesystem_flush_interval_ms--;
+    }
+}
+
+
 static void make_empty_file(FATFS *fatfs, const char *path) {
     FIL fp;
     f_open(fatfs, &fp, path, FA_WRITE | FA_CREATE_ALWAYS);
@@ -91,6 +115,8 @@ void filesystem_init(bool create_allowed, bool force_create) {
 }
 
 void filesystem_flush(void) {
+    // Reset interval before next flush.
+    filesystem_flush_interval_ms = CIRCUITPY_FILESYSTEM_FLUSH_INTERVAL_MS;
     supervisor_flash_flush();
 }